The Effect of the Number of Rotor Slits on the Performance Characteristics of Medium-Speed Solid Rotor Induction Motor

The effect of the number of rotor slits on the electromagnetic torque production, torque ripple, rotor eddy-current loss and the power factor are numerically studied in case of a three phase, two-pole, 200 Hz, solid-rotor induction motor. The number of the stator slots was 48 and the number of the rotor slits was varied from 28 to 36. The depth of the rotor slits was kept at a constant value in all the calculations. The harmonic content of the air-gap flux density as well as the electro-magnetic torque at each rotor slit number were studied in detail. It was also found that when the number of the rotor slits was an odd number, an unsymmetrical magnetic pull affects between the stator and the rotor.